Seventy-five people were on board the westbound Silver Line train July 29 when the fourth and fifth cars of the six-car train collapsed in the middle and jolted off the tracks. The train was about 100 feet east of the East Falls Church station.

In a preliminary report about the incident, the NTSB said the tracks where the train derailed were in "severe" disrepair. The distance between the tracks in the area was nearly two inches wider than the standard set by Metro, according to the NTSB.

Investigators also noted a "severe defective tie condition" in the area where the train derailed, and more than 30 feet of track had defective rail ties.

Four track inspectors and two supervisors were fired after the derailment. Six more track inspectors could be fired or face unpaid suspension. Another 10 are facing possible disciplinary action pending the outcome of the administrative process.

Wiedefeld said the issue of falsifying records gets down to a systemic, cultural issue that needs to be changed at Metro.

No one has been charged with any crime, but the investigation into the incident is ongoing.

"As a union, it is our job to represent the employees. And that's what we will do," Jeter said.

In addition to the disciplinary action, Metro says every interlocking was inspected, six FRA-trained outside track inspectors were embedded to improve Metro's inspection process and the track inspection manual is being rewritten.